Well, I have two cracks in this funky exhaust manifold on my Rover. I'm contemplating a quick fix so I can get the vehicle smogged today (pass or fail, I don't care...I need to at least smog it to get my 24-hour changed to a 10-day moving permit).

Both cracks are easily accessible from the top...should I JB Weld it or braize it using a torch and some bronze rod (or whatever you might recommend)?

I'm planning on replacing the entire exhaust from the headers back, so long-term is not an issue. I just need the vehicle to not be smoking (which it isn't), and not making a suspect amount of racket forcing me into a mandatory fix-it from the DMV (they will force you to spend 3 or 4 hundred dollars at a licensed mechanic -who will undoubtedly be saying "Huh?" the whole time looking at my truck - to fix the "problem" in order to register your vehicle :mad: )
Get it? So what is it...JB Weld or braizing?

COME ON!!!

Do I have to take this question to D-Web?

Glaringly visible cracks? Do they make any noise? Can you SEE any exhaust coming out of them?

I would be careful with the jb weld and the fumes to the O2 sensor if the cracks are huge. If huge, I would braze. or MIG

j

Drill holes at both ends and braze. It really shouldn't be that difficult, once you get it up to operating temp, just think, no preheating necessary and you'll have fairly consistent heating across the manifold.

I question the high temperature longevity of JB weld, that and do you really want the guy at the DMV seeing the JB Weld on a manifold? I'd think that would send them instantly into orbit demanding that "Somebody who knows what they're doing" fix your truck. I didn't mean for that to sound as inflammatory as it might sound!!!

That said, I once saw a forktruck with a cracked block, using JB weld to keep the coolant in.

Tried brazing, didn't go to well. I couldn't get the cast manifold hot enough around the crack to melt the brass. I ran out of oxygen on my torch before I could make any progress.
It's a friggin' weird looking manifold; I'll post a pic when I pull it off.
So I JB Welded it. Well, most of it burned off (and the fumes were pretty noxious), but it appears what JB Weld did stay plugged the crack. Will inspection see it? No. I'll show you why later (when I get a pic).
In the meantime, I'm gonna meet Slade at the dealership this afternoon and we're gonna see if we can finagle some "junked" Y-pipes in on warranty (what's a rattling cat to me?). If so, "new" y-pipe and Slade's old crack-free manifolds should do the trick :)